diameter/lib/components/forms/duration_form_field.dart

import 'package:flutter/material.dart';

class DurationFormField extends StatefulWidget {
  final String label;
  final int minutes;
  final void Function(int?) onChanged;
  final bool showSteppers;
  final bool readOnly;
  final int min;
  final int? max;
  final int step;

  const DurationFormField(
      {Key? key,
      required this.label,
      this.minutes = 0,
      required this.onChanged,
      this.showSteppers = false,
      this.readOnly = false,
      this.min = 0,
      this.max,
      this.step = 5})
      : super(key: key);

  @override
  _DurationFormFieldState createState() => _DurationFormFieldState();
}

class _DurationFormFieldState extends State<DurationFormField> {
  late Duration duration;
  final TextEditingController controller = TextEditingController(text: '');

  @override
  void initState() {
    super.initState();
    updateDuration();
  }

  void updateDuration() {
    duration = Duration(minutes: widget.minutes);

    int days = duration.inDays;
    int hours = duration.inHours - days * 24;
    int minutes = duration.inMinutes - hours * 60;
    int seconds = duration.inSeconds - minutes * 60;

    String daysString = days > 9 ? '$days d' : days > 0 ? '0$days d' : '00 d';
    String hoursString = hours > 9 ? ' $hours h' : hours > 0 ? ' 0$hours h' : ' 00 h';
    String minutesString = minutes > 9 ? ' $minutes m' : minutes > 0 ? ' 0$minutes m' : ' 00 m';
    String secondsString = seconds > 9 ? ' $seconds s' : seconds > 0 ? ' 0$seconds s' : ' 00 s';
    controller.text = '$daysString $hoursString $minutesString $secondsString'.trim();
  }

  void handleChange(String value) async {
    await Future.delayed(const Duration(seconds: 1));

    int days = int.tryParse(value.split(' d')[0]) ?? 0;
    int hours = int.tryParse(value.split('d')[1].split(' h')[0]) ?? 0;
    int minutes = int.tryParse(value.split('h')[1].split(' m')[0]) ?? 0;
    int seconds = int.tryParse(value.split('m')[1].split(' s')[0]) ?? 0;
    int updatedMinutes =
        Duration(days: days, hours: hours, minutes: minutes, seconds: seconds)
            .inMinutes;

    widget.onChanged(updatedMinutes);
    setState(() {
      updateDuration();
    });
  }

  void onIncrease() {
    if (widget.max == null || widget.minutes + widget.step <= widget.max!) {
      int value = widget.minutes + widget.step;
      widget.onChanged(value);
      setState(() {
        updateDuration();
      });
    }
  }

  void onDecrease() {
    if (widget.minutes - widget.step >= widget.min) {
      int value = widget.minutes - widget.step;
      widget.onChanged(value);
      setState(() {
        updateDuration();
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    return Row(
      mainAxisSize: MainAxisSize.min,
      children: [
        widget.showSteppers
            ? IconButton(
                onPressed: onDecrease,
                icon: const Icon(Icons.remove),
              )
            : Container(),
        Expanded(
          child: TextFormField(
            controller: controller,
            decoration: InputDecoration(
              labelText: widget.label,
            ),
            keyboardType: TextInputType.numberWithOptions(
                decimal: true, signed: widget.min.isNegative),
            onChanged: handleChange,
          ),
        ),
        widget.showSteppers
            ? IconButton(
                onPressed: onIncrease,
                icon: const Icon(Icons.add),
              )
            : Container(),
      ],
    );
  }
}